Yo-yo is a popular toy that attracts both children and adults. There are many designs about yo-yo disclosed in prior inventions, such as that named as "Kong-Fu Yo-yo" published in Taiwan under Publication No. 334830. The Kong-Fu Yo-yo includes a rotary that is rotated by manipulating a string wound about the yo-yo. When the rotary rotates, steel balls at two sides of a supporting lever inside the rotary move upward. By utilizing a stress corresponding to the floating steel balls, a shaft of the rotary is allowed to rotate about a bolt. With a restoring spring and a balancing spring provided in the rotary, the supporting lever could automatically restore to a balanced position. These arrangements allow the Kong-Fu Yo-yo to be more easily manipulated to rotate smoothly. The rotary of the Kong-Fu Yo-yo is closed between two side covers. However, the side covers of the Kong-Fu Yo-yo tend to break, separate apart or even be destroyed when the yo-yo collides with a hard ground or wall while being played.
In addition to the disadvantage of being subject to breakage, most of the yo-yos currently available in the markets have similar internal structure and external appearance, making yo-yos not so attractive to consumers as before.
It is therefore desirable to develop a yo-yo having high impact strength and distinctive appearance and being provided with laser emission means and whistles to create more funs for a prolonged period of time.